The impact of long-term biosolids application (>100 years) on soil metal dynamics

Mossa, Abdul Wahab; Bailey, Elizabeth H.; Usman, Abida; Young, Scott D.; Crout, Neil M.J.

Abstract

© 2020 Elsevier B.V. Biosolids application to arable land is a common, and cost-effective, practice but the impact of prolonged disposal remains uncertain. We evaluated the dynamics of potentially toxic elements (PTEs) at a long-established ‘dedicated’ sewage treatment farm. Soil metal concentrations exceeded regulations governing application of biosolids to non-dedicated arable land. However, measurement of isotopic exchangeability of Ni, Cu, Zn, Cd and Pb demonstrated support for the ‘protection hypothesis’ in which biosolids constituents help immobilise potential toxic metals (PTMs). Metal concentrations in a maize crop were strongly, and almost equally, correlated with all ‘capacity-based’ and ‘intensity-based’ estimates of soil metal bioavailability. This was attributable to high correlations between soil factors controlling bioavailability (organic matter, phosphate etc.) on a site receiving a single source of PTMs. Isotopic analysis of the maize crop suggested contributions to foliar Pb from soil dust originating from neighbouring fields. There was also clear evidence of metal-specific effects of biosolids on soil metal lability. With increasing metal concentrations there was both decreasing lability of Cd and Pb, due to interaction with increasing phosphate concentrations, and increasing lability of Ni, Cu and Zn due to weaker soil binding. Such different responses to prolonged biosolids disposal to arable soil should be considered when setting regulatory limits.

Citation

Mossa, A. W., Bailey, E. H., Usman, A., Young, S. D., & Crout, N. M. (2020). The impact of long-term biosolids application (>100 years) on soil metal dynamics. Science of the Total Environment, 720, Article 137441. https://doi.org/10.1016/j.scitotenv.2020.137441

• Journal Article Type: Article
• Acceptance Date: Feb 18, 2020
• Online Publication Date: Feb 20, 2020
• Publication Date: Jun 10, 2020
• Deposit Date: Mar 4, 2020
• Publicly Available Date: Feb 21, 2021
• Journal: Science of the Total Environment
• Print ISSN: 0048-9697
• Electronic ISSN: 1879-1026
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 720
• Article Number: 137441
• DOI: https://doi.org/10.1016/j.scitotenv.2020.137441
• Keywords: Environmental Engineering; Waste Management and Disposal; Pollution; Environmental Chemistry
• Public URL: https://nottingham-repository.worktribe.com/output/4088429
• Additional Information: This article is maintained by: Elsevier; Article Title: The impact of long-term biosolids application (>100 years) on soil metal dynamics; Journal Title: Science of The Total Environment; CrossRef DOI link to publisher maintained version: https://doi.org/10.1016/j.scitotenv.2020.137441; Content Type: article; Copyright: © 2020 Elsevier B.V. All rights reserved.